Apparatus for wiping conduit sections



P 1959 o. BERNHARDT 2,906,237

APPARATUS FOR WIPING CONDUIT SECTIONS Filed March 17. 1955 i 5Sheets-Sheet 1 i l 23 I l 26 36 4 o V 15 a2 47 i 40 I 0 TTO BERNHARDT;

IN V EN TOR.

HUEENER, BE'E'HLER, WORRE'L 8 HERZIG,

A TTORNE Sept. 29, 1959 o. BERNHARDT 2,906,237

APPARATUS FOR WIPING CONDUIT SECTIONS Filed March 17. 1955 3Sheets-Sheet 2 OTTO BERNHARDT,

IN VEN TOR.

HUEBNER, BEEHLER, WORRE L 8 HEIPZ/G,

A TTORNEVS- P 1959 d. BERI\ IHA RDT 2,906,237

- APPARATUS-FOR WIPING CONDUIT SECTIONS Filed March 17. 1955 3Sheets-Sheet 3 OTTO BERIVHARDT;

INVENTOR.

HuEa/vEmaEEr/mk,

WORREL 8 HERZ/G,

ATTORNE K51 United States Patent APPARATUS FOR WIPING CONDUIT SECTIONSOtto Bernhardt, Gardena, Calif., assignor to Rome Cable Corporation,Torrance, Calif., a corporation of New York Application March 17, 1955,Serial No. 494,853 3 Claims. c1. 118-63) The present invention relatesto internally and externally wiping freshly coated conduit sections freeof exproblem becomes even more difiicult when the coating material ishigh melting point material such as a molten metal, for example, appliedto metal conduit sections. A practical example is the wiping of excessmolten zinc from steel conduit sections immediately after removal from azinc pot in the hotedip galvanizing process.

Accordingly, an important object of the present invention is to providea method and apparatus for continuously wiping excess coating materialfrom the surfaces of coated conduit sections without injuring thecoating.

Another object is the provision of an eflicient and auto matic methodand apparatus for continuously withdrawing dip-coated steel conduitsections from a dip-tank and continuously wiping excess coating materialpneumatically from both the internal and external surfaces of theconduit sections.

additional object is to provide a continuous, automatic method andapparatus for pneumatically wiping to a smooth and uniform finish theinternal and external coating of steel conduit sections freshlygalvanized by the hot-dip galvanizing method.

These and other objects will be apparent upon reading the followingdescription.

Broadly stated, the present invention comprehends a method andapparatus, preferably automatic, for pneu- Inatically wiping excesscoating material from conduit .sections, preferably continuously. Itcomprises conveyor means for conveying freshly coated conduit sections,preferably axially thereof, from the coating station to the wipingstation. At the wiping station the coated conduit sections are passedaxiallythrough a nozzle means arranged in a circle, such as a hollowring provided with radially arranged nozzles directed toward the centerof the ring. As the conduit section passes through the nozzlemeans,-stea m or other vapor or gas is ejected from the nozzle means andimpinged against the external surface of the section to pneumaticallywipe or blow the excess coating material therefrom. A second nozzlemeans, adapted to engage an end of the conduit section, is so engagedand air or other gas is blown through the section to wipe or blow excesscoating material from the internal surface thereof. The operation of theconveyor means and the first and second nozzle means preferablyautomatically are actuated and timed for handling each ,COn-

.duit section in a continuous series thereof by suitable means such astime cycle switches.

A more detailed description of a specific embodiment of the method andapparatus of the invention as applied to wiping galvanized steel conduitsections freshly galvanized by the hot-dip method is given withreference to the drawings, wherein;

Figure 1 is a side elevational view of a magnetic roller conveyor andsteam wiper showing a conduit section being conveyed from a zinc pot(not shown);

Figure 2 is a similar view showing the conduit section in position forinternal air wiping;

Figure 3 is a similar View showing the wiped conduit section and themagnetic roller conveyer in position to commence a new cycle ofoperations;

Figure 4 is a detail perspective view showing an air injection nozzlefor internal wiping of galvanized conduit e t Figure 5 is an end view ofthe magnetic roller conveyer taken along the line 5-5 of Figure l andshowing a steam jet ring for external wiping of galvanized conduitsections;

Figure 6 is a detail perspective view of the conduit section carriageemployed with the air and steam wiper;

Figure 7 is a fragmentary plan view showing the end of a conduitsection, partially in section, and supported on the conduit sectioncarriage;

Figure 8 is a detail elevational view, with a portion broken away,showing the steam ring externally Wiping a galvanized conduit sectionpassing through the ring; W

Figure 9 is a cross-sectional view taken on the line 9:..9 of Figure 8showing the relationship of the conduit section to the nozzles of thesteam ring;

Fig. 10 is a schematic diagram illustrating the pneumatic and electricalsystem of the apparatus in sin;- plified form;

Fig. 11 is a vertical cross-sectional view as taken substantially alonga line 11-11 of Fig. 6; i

Fig. 12 is a side view, with parts broken away for greater clarity, asseen substantially along a line 12-12 revolving electromagnetic roller10 in a V-shaped groove 11 (Figure 5) formed peripherally of the rollerin a middle portion thereof and having its bottom side ing away from thezinc pot. Roller 10 attracts the hot galvanized conduit section to thebottom thereof, draws it out of the zinc pot and passes it on to abattery of electromagnetic rollers 12 revolving in the same directionand otherwise resembling roller 10. After the end of the withdrawnconduit section passes beyond the bottom side of the first of the fourrollers 12, it is passed through the circular opening of a ring 13. K

Ring 13, as is best shown in Figures 8 and 9, is hollow and is providedwith a series of radially disposed nozzles 14 passing through the innerwall of the ring and angularly inclined about 20 (Figure 9) from thevertical with their inner ends nearer the conduit entrance side of thering and adjacent the external surface of a condiiit section 15 passingthrough the ring. The ring 13 cornnunicates with a steam pipe 16 towhich it is releasabl y connected by means of links 17 pivotally mountedon" he walls of the steam pipe 16 and carrying pivotally mounted toggles18 for engagement with a collar 19 on i 20 of the ring 13. Thisarrangement permits speedy rfe placement of the ring during minimum shutdown time. The ring 13 can be made with an inner sleeve 13a (Figure 9)provided with a flange at the front end and an external thread at therear end tomesh withan inte a1 As the conduit 15 passes through the ring13, a blast of steam, preferably in the range of about 900 to about1,000 F. is ejected from the ring 13 through the nozzles 14 and causedto impinge on the external surface of the conduit to blow or wipe offexcess amounts of zinc therefrom. When the leading end of the conduit 15passes beyond the third roller 12, it contacts a time cycle switch 21which, when the trailing end of the tube passes over the two projections41 and 42, de-magnetizes the magnetic rollers 12, dropping the tube ontocarriage 27.

Instant de-magnetization of the rollers is accomplished by impressing areverse field on the main electro-magnetic field. The position ofcarriage 27 is determined primarily by two air cylinders 28 and 29attached near each end thereof and suspended from the frame 31 of thewiping and conveying mechanism. As shown in Figure 1, when a conduitsection 15 is conveyed into the wiping apparatus by rollers 12, thecarriage 27 is held by the air cylinders 28 and 29 below the conduitsection and parallel thereto.

When the rollers 12 are de-magnetized and conduit section 15 is dropped,it falls into a V-shaped channel iron or holder 32 (Figure 6) attachedto the upper portion of the carriage 27. Upon falling on channel iron orholder 32, the conduit section 15 actuates a time cycle switch 33mounted in line with the channel 32 and positioned toward the trailingend of the conduit section.

The time cycle switch 33 initiates a series of actions. The operation isbest understood by reference to Fig. 10, in conjunction with the variouspositions illustrated in Figs. 1, 2 and 3; Fig. being a simplifiedschematic diagram illustrating operative portions of the apparatusrelative to pneumatic and electrical systems adapted to automaticallyand cyclically carry out the functions of the apparatus. The switch 33is a time-delay switch having a pair of contacts 51 adapted to close acircuit and energize a solenoid of a solenoid-actuated valve 52 andhaving a source of electrical power indicated at 53 and referred to inbroken lines at 53. The valve 52 diverts pneumatic pressure, from apressure source (not shown) delivered to the valve by a conduit 54, to aconduit 56 communicating with the upper portion of the air cylinder 29to extend its piston rod to lower the rear end of the carriage 27, asshown in Fig. 2, by depressing the lower cnd of a link 34 pivotallyconnected to the frame 31 and to the rear end of the carriage 27. Thelink 34, in its downward movement, actuates a timedelay switch,indicated at 57 in Fig. 10, to energize a coil of a solenoid-actuatedvalve 58 which diverts pneumatic pressure from a branch conduit 54' ofthe conduit 54 into a conduit 59 to cause the air cylnder 36 to retractits piston rod and draw inwardly a gooseneck section of conduit 37 untilair injection nozzle 26 tightly engages the leading end of the conduitsection 15, as best shown in Fig. 2. As the nozzle 26 is actuated intoengagement with the conduit section 15, an arm 61 supporting the nozzle26 closes a circuit 62 to actuate the solenoid of a solenoid-operatedvalve 63, opening the valve to admit steam under pressure into theconduit 37. After a predetermined period of time, the time-delay switch57 de-energizes the coil of the solenoid-actuated valve 58 to cause thecylinder 36 to extend its rod and disengage the nozzle 26 from theconduit and opening the circuit 62 to cause the valve 63 to close and toshut off the steam. On its return travel, the arm 61 closes contact 64of a circuit 66 to energize a solenoid of a solenoid operated valve 67which controls pneumatic pressure to the air cylinder 28. The action andtime cycle of air cylinder 39, mounted on the carriage 27, aredetermined by a cam operated air switch 40 located on the end of thepiston rod of air cylinder 28.

As best seen in Figs. 11-13, the air switch 40 is actuated by thedownward movement of the piston rod of cylinder 28 at the end of thepreceding cycle until about two-thirds of the piston rod has beenextended.

Energizing of the solenoid operated valve 67 causes the cylinder 28 toextend its rod and drop the forward end of the frame 27, therebyrotating a shaft 68 secured to the lower end 69 of the piston rod of thecylinder 28 as the angular relationship between the frame 27 and thepiston rod changes, as best seen in Figs. 12 and 13. A cam 71 is securedto the shaft 68 for rotation therewith, which through a pivoted member72 actuates a valve stem 73 of the air switch or valve 40 to divertpneumatic pressure from a branch conduit 54" of the pressure conduit 54into a conduit 74 communicating with the cylinder 39 to cause thecylinder 39 to actuate lever 43, pivotally mounted in the carriage on arotatable bar 44 to which a post 46 is fixed. In the upper position ofthe carriage 27, the piston rod of the cylinder 39 is extended to bringthe projections 41 and 42 into engagement with the conduit section whichis elevated slightly when the leading end is engaged by the nozzle 26,as previously described, the conduit section being supported on itsends, free of the channel 32, and remains supported at only its ends innozzle 26 and, as shown in Fig. 7, between two projections 41 and 42gripping the terminal edges of the trailing end of the conduit duringthe air injection period.

At this stage, the conduit section 15 is still hot enough to maintainthe excess of zinc thereon in a molten condition. As the conduit section15 is supported only at its extreme ends, it is not cooled by contactwith channel 32 or any other carriage supporting members. A strong blastof air from nozzle 26 is then injected through the internal length ofthe hot conduit section 15 and excess zinc is cleanly wiped or blownfree of the internal surface of the conduit without any occlusionsforming on any cooled internal surfaces. The resulting blast of zinc andair dispels it through the trailing end of the conduit section 15 into acentrifugal cyclone (not shown) wherein the zinc particles are separatedfrom the expelled air.

The air cylinder 36 is then caused, at the end of a predetermined periodof holding by the time-delay switch 57, to extend its piston rod andretract the injection nozzle 26 from the forward end of the conduit 15,and the cylinder 39 retracts projections 41 and 42 from the trailing endof the section while the carriage 27 is being lowered by the cylinder28, the air switch 40 actuating the cylinder 39 as previously described.The conduit section again rests on channel 32 of the carriage 27. Theair cylinder 28 then extends its rod to lower the forward end of thecarriage so that it and the conduit section 15 thereon are lowered to ahorizontal position, as shown in Fig. 3. In so doing, the piston rod onthe air cylinder 28 actuates the air switch 40, as described above. Theconduit section 15, which is at about 700 F. at this stage, then isengaged by a roller conveyor 47 and is conveyed into a chromate bath(not shown). After dipping in the chromate bath to form a conversioncoating of zinc-chromate on the conduit section, it is ready for finalinspection and shipment. The time-delay switch 64 then actuates thecylinder 28, through the valve 67 to retract its piston rod and raisethe frame 27 into a position adjacent the rollers 12. The time-delayswitch 33, at the same time, causes the valve 52 to reverse thepneumatic pressure in cylinder 29 to raise the arm 34 and thereby therearward end of the carriage 27 to its position illustrated in Fig. 1.

The rollers 12 are again magnetized and turned and the above-describedseries of operations is cyclically repeated for each conduit sectionwithdrawn from the zinc bath. The operations of the valves controllingthe steam wipe or blow-off, the air wipe or blow-out, the air cylindersand the magnetization and de-magnetization, and starting and stopping ofthe rollers is controlled by time cycle switches. The timing of each ofthe operations is carefully adjusted so that the entire cycle ofoperations is automatic and continuous.

It will be seen that the hot-dipped conduit sections are wiped free ofexcess adhering zinc to a smooth and uniform finish both internally andexternally by using the specific embodiment of the invention describedand illustrated above. The wiping is done continuously and entirelyautomatically.

In the above description, the invention has been described asspecifically applied to the wiping of ferrous metal conduit sectionscoated with a single coating of zinc. It will be understood, however,that the invention can be applied to wiping conduit sections during theapplication of multiple coatings of zinc or zinc alloys to ferrous metalconduit as well as single or multiple coatings of other metals. Theinvention also can be used in connection with coating conduit or pipemade of metals other than ferrous metals or of non-metallic compositionwith either metallic or non-metallic coatings. For example, theinvention can be applied to wiping metallic conduit sections that havebeen enameled or painted or hot-dipped in pitch, tar or asphalt orcompositions of these materials. Similarly, the invention can be appliedto wiping plastic or other types of non-metallic conduit or piping thathas been coated with liquid or molten coatings in single or multiplelayers.

When non-ferrous or non-magnetic conduit sections are handled by themethod and/or apparatus of the invention, the conveyer rollers and 12are not electromagnetic rollers and the conduit sections are conveyed onthe top side of these rollers through the external wiping ring 13. Theexternally wiped conduit sections are then grasped at the ends by theinternal wiping nozzle 26 and projections 41 and 42, or theirequivalent, and the conduit section is hoisted somewhat above therollers 12, or their equivalent, while the internal pneumatic wipingblast is effected. After the internal surface Wiping is completed, thewiped conduit section is placed on a conveyer 47 and the above cycle ofoperations is continuously and automatically repeated.

Although certain structures and design features have been shown indescribing the specific embodiment of the invention shown, includingstructure and design of certain auxiliary equipment and drive means, itwill be understood that such features can be varied and modifiedconsiderably as to details and structure, as will occur to one skilledin the art. Accordingly, although a specific embodiment of the inventionhas been described above, it will be understood that such changes andmodifications in the method and apparatus of the invention can be madewithin the scope of the appended claims without departing from thespirit of the invention.

What is claimed is:

1. In an apparatus for wiping excess coating material from a section ofa conduit; a nozzle arranged to engage one end edge of said conduit andto direct a blast of gas therethrough, a support engageable with theother end edge of said conduit, and clamping means for urging saidsupport toward said nozzle to clamp and support said conduit sectiontherebetween free of any intermediate support and free of contact withany portion of said apparatus between the ends of said conduit section.

2. Apparatus as defined in claim 1 wherein said support comprises spacedportions engageable with opposed edge portions of said conduit endwhereby to provide a passageway therebetween for exhaust of gas andexcess coating material from the interior of said conduit.

3. Apparatus as defined in claim 1 including a holder, means fordelivering a section of said conduit to said holder, and meansresponsive to arrival of said conduit on said holder for actuating saidclamping means, said support being arranged to simultaneously move saidconduit free of said holder and into clamping engagement with saidnozzle.

References Cited in the file of this patent UNITED STATES PATENTS1,124,727 Greenfield Ian. 12, 1915 1,906,400 Moon May 2, 1933 1,917,918Bedell July 11, 1933 2,424,808 Eckman July 29, 1947 2,495,093 EckmanIan. 17, 1950 2,606,846 Pearson Aug. 12, 1952 2,669,217 Pearson Feb. 16,1954

